(a) Field of the Invention
The present invention is related to an art of presenting LED light emitting efficiency and light color, and more particularly, to a multi-wavelength LED construction and its manufacturing process that produce highly light emitting efficiency and accurate gloss.
(b) Description of the Prior Art
As illustrated in FIG. 1 for a schematic view of a basic construction of a multi-wavelength LED of the prior art, a chip mounting gel 40 is used to place a light-emitting chip 10 in a bowl shaped carrier 20; a golden plated wire 30 constitutes the connection between the blue light emitting chip 10 and two electrodes 21; and a fluorescent gel 50 containing fluorescent powders is applied to cover up the light-emitting chip 10. When the light-emitting chip 10 is conducted, the fluorescent powders in the fluorescent gel 50 are excited by the light source from the light-emitting chip 10 to emit the light in an expected color.
Generally, a blue chip is used in the multi-wavelength LED to excite yellow fluorescent powders 51 mixed in the fluorescent gel 50 to produce pseudo-white light that looks light white light. However, the prior art relies upon only fluorescent powders in a straight color as the complementary light excited by the light-emitting chip, the resultant pseudo-white gloss is poor and blamed for yellow halo phenomenon. To correct, two types of fluorescent powders in different colors are mixed in the fluorescent gel for the multi-wavelength LED. Usually, a blue chip is used to excite red fluorescent powders 52 and green fluorescent 53 mixed in the fluorescent gel 50 for the red light and the green light to incorporated with the blue light of the light-emitting chip 10 for obtaining RGB mixing results to produce the light color that is with higher color development properties and closer to the white light. However, the amount and proportion of the fluorescent powders in different colors prevent easy control for effective control of the quality of the finished product; and interference exists due to that different colors of fluorescent powders are excited at the same position at the same time by the light source from the light-emitting chip. That is, the energy for the fluorescent powder of shorter wavelength will be absorbed by that of longer wavelength to prevent estimate of their consumption ratio, and thus to fail the expected color deflection for presenting the accurate expected light color. Furthermore, the fluorescent powder of shorter wavelength emits light of slightly longer wavelength which in turn excites the fluorescent powder to emit light of even longer wavelength thus to compromise the light emitting efficiency to produce light at lower luminance.